Three-dimensional (3D) printing (e.g., additive manufacturing) is a process for making a three-dimensional (3D) object of any shape from a design. The design may be in the form of a data source such as an electronic data source or may be in the form of a hard copy. The hard copy may be a two-dimensional representation of a 3D object. The data source may be an electronic 3D model. 3D printing may be accomplished through an additive process in which successive layers of material are laid down one on top of each other. This process may be controlled (e.g., computer controlled, manually controlled, or both). A 3D printer can be an industrial robot.
3D printing can generate custom parts quickly and efficiently. A variety of materials can be used in a 3D printing process including elemental metal, metal alloy, ceramic, elemental carbon, or polymeric material. In a typical additive 3D printing process, a first material-layer is formed, and thereafter, successive material-layers (or parts thereof) are added one by one, wherein each new material-layer is added on a pre-formed material-layer, until the entire designed three-dimensional structure (3D object) is materialized.
3D models may be created utilizing a computer aided design package or via 3D scanner. The manual modeling process of preparing geometric data for 3D computer graphics may be like plastic arts, such as sculpting or animating. 3D scanning is a process of analyzing and collecting digital data on the shape and appearance of a real object. Based on this data, 3D models of the scanned object can be produced. The 3D models may include computer-aided design (CAD).
A large number of additive processes are currently available. They may differ in the manner layers are deposited to create the materialized structure. They may vary in the material or materials that are used to generate the designed structure. Some methods melt or soften material to produce the layers. Examples for 3D printing methods include selective laser melting (SLM), selective laser sintering (SLS), direct metal laser sintering (DMLS), shape deposition manufacturing (SDM) or fused deposition modeling (FDM). Other methods cure liquid materials using different technologies such as stereo lithography (SLA). In the method of laminated object manufacturing (LOM), thin layers (made inter alia of paper, polymer, metal) are cut to shape and joined together.
Sometimes, it is requested to control the microstructure of a 3D object to form a specific type or types of microstructure (e.g., grain (e.g., crystal) structure and/or metallurgical microstructure). At times, it is requested to fabricate a 3D object including complex topology (e.g., intricate, and/or fine microstructures). For example, the 3D object may comprise overhangs (e.g., ledges), and/or cavities. Occasionally, it is requested to fabricate a 3D object with varied materials and/or material structures in specific portions of the 3D object. The present disclosure describes formation of such requested 3D objects. In some instances, it is requested to control the way at least a portion of a layer of hardened material is formed. The layer of hardened material may comprise a multiplicity of melt pools. In some instances, it may be requested to control one or more characteristics of the melt pool that forms the layer of hardened material.
At times, the printed 3D object may bend, warp, roll, curl, or otherwise deform during the 3D printing process. Auxiliary supports may be inserted to circumvent the deformation. These auxiliary supports may be subsequently removed from the printed 3D object to produce a requested 3D product (e.g., 3D object). The presence of auxiliary supports may increase the cost and time required to manufacture the 3D object. At times, the requirement for the presence of auxiliary supports hinders (e.g., prevent) formation of cavities and/or ledges in the requested 3D object. The requirement for the presence of auxiliary supports may place constraints on the design of 3D objects, and/or on their respective materialization. In some embodiments, the inventions in the present disclosure facilitate the generation of 3D objects with reduced degree of deformation. In some embodiments, the inventions in the present disclosure facilitate generation of 3D objects that are fabricated with diminished number (e.g., absence) of auxiliary supports (e.g., without auxiliary supports). In some embodiments, the inventions in the present disclosure facilitate generation of 3D objects with diminished amount of design and/or fabrication constraints (referred to herein as “constraint-less 3D object”).